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Re: Books





Aquatic Plants Digest wrote:

> Date: Thu, 10 Dec 1998 12:16:19 -0500
> From: Romano <romano at pathway1_pathcom.com>
> Subject: Re: Books
> 
> Karen Randall has asked the question, "Can you believe the books?" and I
> would be interested to hear fron any chemist who could possibly comment on
> her statement that:
> "Ammonia and ammonium exist in equilibrium", in response to my statement
> that, "Ammonia is called ammonium in water with a PH less than 7."

Spotte's _Fish and Invertibrate Culture_ (Wiley) discusses such
equilibrium situations at some length, with particular emphasis on
ammonia/ammonium. He even has a big table giving values at various pH
levels.

"Equilibrium" does not mean they are equal. It means the ratio of one to
the other becomes stable at a given pH and temperature. The ratio of
ammonia to ammonium goes from really negligible below pH=6.5 or so, to
about 1/3 at pH=9. Since an amount of ammonia <0.01ppm has been shown to
cause irreversible gill damage, it pays to understand this relationship
very well.

Wright

-- 
Wright Huntley, Fremont CA, USA, 510 494-8679  huntley1 at home dot com
          *********   Eschew obfuscation   **********